32bpp_base.hpp

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/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */
 
#ifndef BLITTER_32BPP_BASE_HPP
#define BLITTER_32BPP_BASE_HPP
 
#include "base.hpp"
#include "../gfx_func.h"
#include "../palette_func.h"
 
class Blitter_32bppBase : public Blitter {
public:
  uint8_t GetScreenDepth() override { return 32; }
  void *MoveTo(void *video, int x, int y) override;
  void SetPixel(void *video, int x, int y, uint8_t colour) override;
  void DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8_t colour, int width, int dash) override;
  void DrawRect(void *video, int width, int height, uint8_t colour) override;
  void CopyFromBuffer(void *video, const void *src, int width, int height) override;
  void CopyToBuffer(const void *video, void *dst, int width, int height) override;
  void CopyImageToBuffer(const void *video, void *dst, int width, int height, int dst_pitch) override;
  void ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y) override;
  size_t BufferSize(uint width, uint height) override;
  void PaletteAnimate(const Palette &palette) override;
  Blitter::PaletteAnimation UsePaletteAnimation() override;
 
  static inline Colour LookupColourInPalette(uint index)
  {
    return _cur_palette.palette[index];
  }
 
  static inline Colour ComposeColourRGBANoCheck(uint r, uint g, uint b, uint a, Colour current)
  {
    uint cr = current.r;
    uint cg = current.g;
    uint cb = current.b;
 
    /* The 256 is wrong, it should be 255, but 256 is much faster... */
    return Colour(
              ((int)(r - cr) * a) / 256 + cr,
              ((int)(g - cg) * a) / 256 + cg,
              ((int)(b - cb) * a) / 256 + cb);
  }
 
  static inline Colour ComposeColourRGBA(uint r, uint g, uint b, uint a, Colour current)
  {
    if (a == 0) return current;
    if (a >= 255) return Colour(r, g, b);
 
    return ComposeColourRGBANoCheck(r, g, b, a, current);
  }
 
  static inline Colour ComposeColourPANoCheck(Colour colour, uint a, Colour current)
  {
    uint r  = colour.r;
    uint g  = colour.g;
    uint b  = colour.b;
 
    return ComposeColourRGBANoCheck(r, g, b, a, current);
  }
 
  static inline Colour ComposeColourPA(Colour colour, uint a, Colour current)
  {
    if (a == 0) return current;
    if (a >= 255) {
      colour.a = 255;
      return colour;
    }
 
    return ComposeColourPANoCheck(colour, a, current);
  }
 
  static inline Colour MakeTransparent(Colour colour, uint nom, uint denom = 256)
  {
    uint r = colour.r;
    uint g = colour.g;
    uint b = colour.b;
 
    return Colour(r * nom / denom, g * nom / denom, b * nom / denom);
  }
 
  static inline uint8_t MakeDark(uint8_t r, uint8_t g, uint8_t b)
  {
    /* Magic-numbers are ~66% of those used in MakeGrey() */
    return ((r * 13063) + (g * 25647) + (b * 4981)) / 65536;
  }
 
  static inline Colour MakeDark(Colour colour)
  {
    uint8_t d = MakeDark(colour.r, colour.g, colour.b);
 
    return Colour(d, d, d);
  }
 
  static inline Colour MakeGrey(Colour colour)
  {
    uint r = colour.r;
    uint g = colour.g;
    uint b = colour.b;
 
    /* To avoid doubles and stuff, multiple it with a total of 65536 (16bits), then
     *  divide by it to normalize the value to a byte again. See heightmap.cpp for
     *  information about the formula. */
    uint grey = ((r * 19595) + (g * 38470) + (b * 7471)) / 65536;
 
    return Colour(grey, grey, grey);
  }
};
 
#endif /* BLITTER_32BPP_BASE_HPP */